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Resolution of sensory ambiguities for gaze stabilization requires a second neural integratorThe ability to simultaneously move in the world and maintain stable visual perception depends critically on the contribution of vestibulo-ocular reflexes (VORs) to gaze stabilization. It is traditionally believed that semicircular canal signals drive compensatory responses to rotational head disturbances (rotational VOR), whereas otolith signals compensate for translational movements [translational VOR (TVOR)]. However, a sensory ambiguity exists because otolith afferents are activated similarly during head translations and reorientations relative to gravity (i.e., tilts). Extra-otolith cues are, therefore, necessary to ensure that dynamic head tilts do not elicit a TVOR. To investigate how extra-otolith signals contribute, we characterized the temporal and viewing distance-dependent properties of a TVOR elicited in the absence of a lateral acceleration stimulus to the otoliths during combined translational/rotational motion. We show that, in addition to otolith signals, angular head position signals derived by integrating sensory canal information drive the TVOR. A physiological basis for these results is proposed in a model with two distinct integration steps. Upstream of the well known oculomotor velocity-to-position neural integrator, the model incorporates a separate integration element that could represent the "velocity storage integrator," whose functional role in the oculomotor system has so far remained controversial. We propose that a key functional purpose of the velocity storage network is to temporally integrate semicircular canal signals, so that they may be used to extract translation information from ambiguous otolith afferent signals in the natural and functionally relevant bandwidth of head movements.
Document ID
20040087490
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Green, Andrea M.
(Washington University School of Medicine St. Louis, Missouri 63110, United States)
Angelaki, Dora E.
Date Acquired
August 21, 2013
Publication Date
October 15, 2003
Publication Information
Publication: The Journal of neuroscience : the official journal of the Society for Neuroscience
Volume: 23
Issue: 28
ISSN: 0270-6474
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: DC04260
CONTRACT_GRANT: F32-DC05271
CONTRACT_GRANT: EY12814
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Program Fundamental Space Biology
NASA Discipline Neuroscience

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